Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Elantech Touchpad driver (v6)
 *
 * Copyright (C) 2007-2009 Arjan Opmeer <arjan@opmeer.net>
 *
 * Trademarks are the property of their respective owners.
 */

#include <linux/delay.h>
#include <linux/dmi.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/input/mt.h>
#include <linux/platform_device.h>
#include <linux/serio.h>
#include <linux/libps2.h>
#include <asm/unaligned.h>
#include "psmouse.h"
#include "elantech.h"
#include "elan_i2c.h"

#define elantech_debug(fmt, ...)					\
	do {								\
		if (etd->info.debug)					\
			psmouse_printk(KERN_DEBUG, psmouse,		\
					fmt, ##__VA_ARGS__);		\
	} while (0)

/*
 * Send a Synaptics style sliced query command
 */
static int synaptics_send_cmd(struct psmouse *psmouse, unsigned char c,
				unsigned char *param)
{
	if (ps2_sliced_command(&psmouse->ps2dev, c) ||
	    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
		psmouse_err(psmouse, "%s query 0x%02x failed.\n", __func__, c);
		return -1;
	}

	return 0;
}

/*
 * V3 and later support this fast command
 */
static int elantech_send_cmd(struct psmouse *psmouse, unsigned char c,
				unsigned char *param)
{
	struct ps2dev *ps2dev = &psmouse->ps2dev;

	if (ps2_command(ps2dev, NULL, ETP_PS2_CUSTOM_COMMAND) ||
	    ps2_command(ps2dev, NULL, c) ||
	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
		psmouse_err(psmouse, "%s query 0x%02x failed.\n", __func__, c);
		return -1;
	}

	return 0;
}

/*
 * A retrying version of ps2_command
 */
static int elantech_ps2_command(struct psmouse *psmouse,
				unsigned char *param, int command)
{
	struct ps2dev *ps2dev = &psmouse->ps2dev;
	struct elantech_data *etd = psmouse->private;
	int rc;
	int tries = ETP_PS2_COMMAND_TRIES;

	do {
		rc = ps2_command(ps2dev, param, command);
		if (rc == 0)
			break;
		tries--;
		elantech_debug("retrying ps2 command 0x%02x (%d).\n",
				command, tries);
		msleep(ETP_PS2_COMMAND_DELAY);
	} while (tries > 0);

	if (rc)
		psmouse_err(psmouse, "ps2 command 0x%02x failed.\n", command);

	return rc;
}

/*
 * Send an Elantech style special command to read 3 bytes from a register
 */
static int elantech_read_reg_params(struct psmouse *psmouse, u8 reg, u8 *param)
{
	if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
	    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
	    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
	    elantech_ps2_command(psmouse, NULL, reg) ||
	    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
		psmouse_err(psmouse,
			    "failed to read register %#02x\n", reg);
		return -EIO;
	}

	return 0;
}

/*
 * Send an Elantech style special command to write a register with a parameter
 */
static int elantech_write_reg_params(struct psmouse *psmouse, u8 reg, u8 *param)
{
	if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
	    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
	    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
	    elantech_ps2_command(psmouse, NULL, reg) ||
	    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
	    elantech_ps2_command(psmouse, NULL, param[0]) ||
	    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
	    elantech_ps2_command(psmouse, NULL, param[1]) ||
	    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
		psmouse_err(psmouse,
			    "failed to write register %#02x with value %#02x%#02x\n",
			    reg, param[0], param[1]);
		return -EIO;
	}

	return 0;
}

/*
 * Send an Elantech style special command to read a value from a register
 */
static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
				unsigned char *val)
{
	struct elantech_data *etd = psmouse->private;
	unsigned char param[3];
	int rc = 0;

	if (reg < 0x07 || reg > 0x26)
		return -1;

	if (reg > 0x11 && reg < 0x20)
		return -1;

	switch (etd->info.hw_version) {
	case 1:
		if (ps2_sliced_command(&psmouse->ps2dev, ETP_REGISTER_READ) ||
		    ps2_sliced_command(&psmouse->ps2dev, reg) ||
		    ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
			rc = -1;
		}
		break;

	case 2:
		if (elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
		    elantech_ps2_command(psmouse,  NULL, ETP_REGISTER_READ) ||
		    elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
		    elantech_ps2_command(psmouse,  NULL, reg) ||
		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
			rc = -1;
		}
		break;

	case 3 ... 4:
		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
		    elantech_ps2_command(psmouse, NULL, reg) ||
		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
			rc = -1;
		}
		break;
	}

	if (rc)
		psmouse_err(psmouse, "failed to read register 0x%02x.\n", reg);
	else if (etd->info.hw_version != 4)
		*val = param[0];
	else
		*val = param[1];

	return rc;
}

/*
 * Send an Elantech style special command to write a register with a value
 */
static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
				unsigned char val)
{
	struct elantech_data *etd = psmouse->private;
	int rc = 0;

	if (reg < 0x07 || reg > 0x26)
		return -1;

	if (reg > 0x11 && reg < 0x20)
		return -1;

	switch (etd->info.hw_version) {
	case 1:
		if (ps2_sliced_command(&psmouse->ps2dev, ETP_REGISTER_WRITE) ||
		    ps2_sliced_command(&psmouse->ps2dev, reg) ||
		    ps2_sliced_command(&psmouse->ps2dev, val) ||
		    ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11)) {
			rc = -1;
		}
		break;

	case 2:
		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_WRITE) ||
		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
		    elantech_ps2_command(psmouse, NULL, reg) ||
		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
		    elantech_ps2_command(psmouse, NULL, val) ||
		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
			rc = -1;
		}
		break;

	case 3:
		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
		    elantech_ps2_command(psmouse, NULL, reg) ||
		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
		    elantech_ps2_command(psmouse, NULL, val) ||
		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
			rc = -1;
		}
		break;

	case 4:
		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
		    elantech_ps2_command(psmouse, NULL, reg) ||
		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
		    elantech_ps2_command(psmouse, NULL, val) ||
		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
			rc = -1;
		}
		break;
	}

	if (rc)
		psmouse_err(psmouse,
			    "failed to write register 0x%02x with value 0x%02x.\n",
			    reg, val);

	return rc;
}

/*
 * Dump a complete mouse movement packet to the syslog
 */
static void elantech_packet_dump(struct psmouse *psmouse)
{
	psmouse_printk(KERN_DEBUG, psmouse, "PS/2 packet [%*ph]\n",
		       psmouse->pktsize, psmouse->packet);
}

/*
 * Advertise INPUT_PROP_BUTTONPAD for clickpads. The testing of bit 12 in
 * fw_version for this is based on the following fw_version & caps table:
 *
 * Laptop-model:           fw_version:     caps:           buttons:
 * Acer S3                 0x461f00        10, 13, 0e      clickpad
 * Acer S7-392             0x581f01        50, 17, 0d      clickpad
 * Acer V5-131             0x461f02        01, 16, 0c      clickpad
 * Acer V5-551             0x461f00        ?               clickpad
 * Asus K53SV              0x450f01        78, 15, 0c      2 hw buttons
 * Asus G46VW              0x460f02        00, 18, 0c      2 hw buttons
 * Asus G750JX             0x360f00        00, 16, 0c      2 hw buttons
 * Asus TP500LN            0x381f17        10, 14, 0e      clickpad
 * Asus X750JN             0x381f17        10, 14, 0e      clickpad
 * Asus UX31               0x361f00        20, 15, 0e      clickpad
 * Asus UX32VD             0x361f02        00, 15, 0e      clickpad
 * Avatar AVIU-145A2       0x361f00        ?               clickpad
 * Fujitsu CELSIUS H760    0x570f02        40, 14, 0c      3 hw buttons (**)
 * Fujitsu CELSIUS H780    0x5d0f02        41, 16, 0d      3 hw buttons (**)
 * Fujitsu LIFEBOOK E544   0x470f00        d0, 12, 09      2 hw buttons
 * Fujitsu LIFEBOOK E546   0x470f00        50, 12, 09      2 hw buttons
 * Fujitsu LIFEBOOK E547   0x470f00        50, 12, 09      2 hw buttons
 * Fujitsu LIFEBOOK E554   0x570f01        40, 14, 0c      2 hw buttons
 * Fujitsu LIFEBOOK E557   0x570f01        40, 14, 0c      2 hw buttons
 * Fujitsu T725            0x470f01        05, 12, 09      2 hw buttons
 * Fujitsu H730            0x570f00        c0, 14, 0c      3 hw buttons (**)
 * Gigabyte U2442          0x450f01        58, 17, 0c      2 hw buttons
 * Lenovo L430             0x350f02        b9, 15, 0c      2 hw buttons (*)
 * Lenovo L530             0x350f02        b9, 15, 0c      2 hw buttons (*)
 * Samsung NF210           0x150b00        78, 14, 0a      2 hw buttons
 * Samsung NP770Z5E        0x575f01        10, 15, 0f      clickpad
 * Samsung NP700Z5B        0x361f06        21, 15, 0f      clickpad
 * Samsung NP900X3E-A02    0x575f03        ?               clickpad
 * Samsung NP-QX410        0x851b00        19, 14, 0c      clickpad
 * Samsung RC512           0x450f00        08, 15, 0c      2 hw buttons
 * Samsung RF710           0x450f00        ?               2 hw buttons
 * System76 Pangolin       0x250f01        ?               2 hw buttons
 * (*) + 3 trackpoint buttons
 * (**) + 0 trackpoint buttons
 * Note: Lenovo L430 and Lenovo L530 have the same fw_version/caps
 */
static inline int elantech_is_buttonpad(struct elantech_device_info *info)
{
	return info->fw_version & 0x001000;
}

/*
 * Interpret complete data packets and report absolute mode input events for
 * hardware version 1. (4 byte packets)
 */
static void elantech_report_absolute_v1(struct psmouse *psmouse)
{
	struct input_dev *dev = psmouse->dev;
	struct elantech_data *etd = psmouse->private;
	unsigned char *packet = psmouse->packet;
	int fingers;

	if (etd->info.fw_version < 0x020000) {
		/*
		 * byte 0:  D   U  p1  p2   1  p3   R   L
		 * byte 1:  f   0  th  tw  x9  x8  y9  y8
		 */
		fingers = ((packet[1] & 0x80) >> 7) +
				((packet[1] & 0x30) >> 4);
	} else {
		/*
		 * byte 0: n1  n0  p2  p1   1  p3   R   L
		 * byte 1:  0   0   0   0  x9  x8  y9  y8
		 */
		fingers = (packet[0] & 0xc0) >> 6;
	}

	if (etd->info.jumpy_cursor) {
		if (fingers != 1) {
			etd->single_finger_reports = 0;
		} else if (etd->single_finger_reports < 2) {
			/* Discard first 2 reports of one finger, bogus */
			etd->single_finger_reports++;
			elantech_debug("discarding packet\n");
			return;
		}
	}

	input_report_key(dev, BTN_TOUCH, fingers != 0);

	/*
	 * byte 2: x7  x6  x5  x4  x3  x2  x1  x0
	 * byte 3: y7  y6  y5  y4  y3  y2  y1  y0
	 */
	if (fingers) {
		input_report_abs(dev, ABS_X,
			((packet[1] & 0x0c) << 6) | packet[2]);
		input_report_abs(dev, ABS_Y,
			etd->y_max - (((packet[1] & 0x03) << 8) | packet[3]));
	}

	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);

	psmouse_report_standard_buttons(dev, packet[0]);

	if (etd->info.fw_version < 0x020000 &&
	    (etd->info.capabilities[0] & ETP_CAP_HAS_ROCKER)) {
		/* rocker up */
		input_report_key(dev, BTN_FORWARD, packet[0] & 0x40);
		/* rocker down */
		input_report_key(dev, BTN_BACK, packet[0] & 0x80);
	}

	input_sync(dev);
}

static void elantech_set_slot(struct input_dev *dev, int slot, bool active,
			      unsigned int x, unsigned int y)
{
	input_mt_slot(dev, slot);
	input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
	if (active) {
		input_report_abs(dev, ABS_MT_POSITION_X, x);
		input_report_abs(dev, ABS_MT_POSITION_Y, y);
	}
}

/* x1 < x2 and y1 < y2 when two fingers, x = y = 0 when not pressed */
static void elantech_report_semi_mt_data(struct input_dev *dev,
					 unsigned int num_fingers,
					 unsigned int x1, unsigned int y1,
					 unsigned int x2, unsigned int y2)
{
	elantech_set_slot(dev, 0, num_fingers != 0, x1, y1);
	elantech_set_slot(dev, 1, num_fingers >= 2, x2, y2);
}

/*
 * Interpret complete data packets and report absolute mode input events for
 * hardware version 2. (6 byte packets)
 */
static void elantech_report_absolute_v2(struct psmouse *psmouse)
{
	struct elantech_data *etd = psmouse->private;
	struct input_dev *dev = psmouse->dev;
	unsigned char *packet = psmouse->packet;
	unsigned int fingers, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
	unsigned int width = 0, pres = 0;

	/* byte 0: n1  n0   .   .   .   .   R   L */
	fingers = (packet[0] & 0xc0) >> 6;

	switch (fingers) {
	case 3:
		/*
		 * Same as one finger, except report of more than 3 fingers:
		 * byte 3:  n4  .   w1  w0   .   .   .   .
		 */
		if (packet[3] & 0x80)
			fingers = 4;
		fallthrough;
	case 1:
		/*
		 * byte 1:  .   .   .   .  x11 x10 x9  x8
		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
		 */
		x1 = ((packet[1] & 0x0f) << 8) | packet[2];
		/*
		 * byte 4:  .   .   .   .  y11 y10 y9  y8
		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
		 */
		y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);

		pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
		width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
		break;

	case 2:
		/*
		 * The coordinate of each finger is reported separately
		 * with a lower resolution for two finger touches:
		 * byte 0:  .   .  ay8 ax8  .   .   .   .
		 * byte 1: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
		 */
		x1 = (((packet[0] & 0x10) << 4) | packet[1]) << 2;
		/* byte 2: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 */
		y1 = etd->y_max -
			((((packet[0] & 0x20) << 3) | packet[2]) << 2);
		/*
		 * byte 3:  .   .  by8 bx8  .   .   .   .
		 * byte 4: bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0
		 */
		x2 = (((packet[3] & 0x10) << 4) | packet[4]) << 2;
		/* byte 5: by7 by8 by5 by4 by3 by2 by1 by0 */
		y2 = etd->y_max -
			((((packet[3] & 0x20) << 3) | packet[5]) << 2);

		/* Unknown so just report sensible values */
		pres = 127;
		width = 7;
		break;
	}

	input_report_key(dev, BTN_TOUCH, fingers != 0);
	if (fingers != 0) {
		input_report_abs(dev, ABS_X, x1);
		input_report_abs(dev, ABS_Y, y1);
	}
	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
	input_report_key(dev, BTN_TOOL_QUADTAP, fingers == 4);
	psmouse_report_standard_buttons(dev, packet[0]);
	if (etd->info.reports_pressure) {
		input_report_abs(dev, ABS_PRESSURE, pres);
		input_report_abs(dev, ABS_TOOL_WIDTH, width);
	}

	input_sync(dev);
}

static void elantech_report_trackpoint(struct psmouse *psmouse,
				       int packet_type)
{
	/*
	 * byte 0:  0   0  sx  sy   0   M   R   L
	 * byte 1:~sx   0   0   0   0   0   0   0
	 * byte 2:~sy   0   0   0   0   0   0   0
	 * byte 3:  0   0 ~sy ~sx   0   1   1   0
	 * byte 4: x7  x6  x5  x4  x3  x2  x1  x0
	 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
	 *
	 * x and y are written in two's complement spread
	 * over 9 bits with sx/sy the relative top bit and
	 * x7..x0 and y7..y0 the lower bits.
	 * The sign of y is opposite to what the input driver
	 * expects for a relative movement
	 */

	struct elantech_data *etd = psmouse->private;
	struct input_dev *tp_dev = etd->tp_dev;
	unsigned char *packet = psmouse->packet;
	int x, y;
	u32 t;

	t = get_unaligned_le32(&packet[0]);

	switch (t & ~7U) {
	case 0x06000030U:
	case 0x16008020U:
	case 0x26800010U:
	case 0x36808000U:

		/*
		 * This firmware misreport coordinates for trackpoint
		 * occasionally. Discard packets outside of [-127, 127] range
		 * to prevent cursor jumps.
		 */
		if (packet[4] == 0x80 || packet[5] == 0x80 ||
		    packet[1] >> 7 == packet[4] >> 7 ||
		    packet[2] >> 7 == packet[5] >> 7) {
			elantech_debug("discarding packet [%6ph]\n", packet);
			break;

		}
		x = packet[4] - (int)((packet[1]^0x80) << 1);
		y = (int)((packet[2]^0x80) << 1) - packet[5];

		psmouse_report_standard_buttons(tp_dev, packet[0]);

		input_report_rel(tp_dev, REL_X, x);
		input_report_rel(tp_dev, REL_Y, y);

		input_sync(tp_dev);

		break;

	default:
		/* Dump unexpected packet sequences if debug=1 (default) */
		if (etd->info.debug == 1)
			elantech_packet_dump(psmouse);

		break;
	}
}

/*
 * Interpret complete data packets and report absolute mode input events for
 * hardware version 3. (12 byte packets for two fingers)
 */
static void elantech_report_absolute_v3(struct psmouse *psmouse,
					int packet_type)
{
	struct input_dev *dev = psmouse->dev;
	struct elantech_data *etd = psmouse->private;
	unsigned char *packet = psmouse->packet;
	unsigned int fingers = 0, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
	unsigned int width = 0, pres = 0;

	/* byte 0: n1  n0   .   .   .   .   R   L */
	fingers = (packet[0] & 0xc0) >> 6;

	switch (fingers) {
	case 3:
	case 1:
		/*
		 * byte 1:  .   .   .   .  x11 x10 x9  x8
		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
		 */
		x1 = ((packet[1] & 0x0f) << 8) | packet[2];
		/*
		 * byte 4:  .   .   .   .  y11 y10 y9  y8
		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
		 */
		y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
		break;

	case 2:
		if (packet_type == PACKET_V3_HEAD) {
			/*
			 * byte 1:   .    .    .    .  ax11 ax10 ax9  ax8
			 * byte 2: ax7  ax6  ax5  ax4  ax3  ax2  ax1  ax0
			 */
			etd->mt[0].x = ((packet[1] & 0x0f) << 8) | packet[2];
			/*
			 * byte 4:   .    .    .    .  ay11 ay10 ay9  ay8
			 * byte 5: ay7  ay6  ay5  ay4  ay3  ay2  ay1  ay0
			 */
			etd->mt[0].y = etd->y_max -
				(((packet[4] & 0x0f) << 8) | packet[5]);
			/*
			 * wait for next packet
			 */
			return;
		}

		/* packet_type == PACKET_V3_TAIL */
		x1 = etd->mt[0].x;
		y1 = etd->mt[0].y;
		x2 = ((packet[1] & 0x0f) << 8) | packet[2];
		y2 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
		break;
	}

	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
	width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);

	input_report_key(dev, BTN_TOUCH, fingers != 0);
	if (fingers != 0) {
		input_report_abs(dev, ABS_X, x1);
		input_report_abs(dev, ABS_Y, y1);
	}
	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);

	/* For clickpads map both buttons to BTN_LEFT */
	if (elantech_is_buttonpad(&etd->info))
		input_report_key(dev, BTN_LEFT, packet[0] & 0x03);
	else
		psmouse_report_standard_buttons(dev, packet[0]);

	input_report_abs(dev, ABS_PRESSURE, pres);
	input_report_abs(dev, ABS_TOOL_WIDTH, width);

	input_sync(dev);
}

static void elantech_input_sync_v4(struct psmouse *psmouse)
{
	struct input_dev *dev = psmouse->dev;
	struct elantech_data *etd = psmouse->private;
	unsigned char *packet = psmouse->packet;

	/* For clickpads map both buttons to BTN_LEFT */
	if (elantech_is_buttonpad(&etd->info))
		input_report_key(dev, BTN_LEFT, packet[0] & 0x03);
	else
		psmouse_report_standard_buttons(dev, packet[0]);

	input_mt_report_pointer_emulation(dev, true);
	input_sync(dev);
}

static void process_packet_status_v4(struct psmouse *psmouse)
{
	struct input_dev *dev = psmouse->dev;
	unsigned char *packet = psmouse->packet;
	unsigned fingers;
	int i;

	/* notify finger state change */
	fingers = packet[1] & 0x1f;
	for (i = 0; i < ETP_MAX_FINGERS; i++) {
		if ((fingers & (1 << i)) == 0) {
			input_mt_slot(dev, i);
			input_mt_report_slot_state(dev, MT_TOOL_FINGER, false);
		}
	}

	elantech_input_sync_v4(psmouse);
}

static void process_packet_head_v4(struct psmouse *psmouse)
{
	struct input_dev *dev = psmouse->dev;
	struct elantech_data *etd = psmouse->private;
	unsigned char *packet = psmouse->packet;
	int id;
	int pres, traces;

	id = ((packet[3] & 0xe0) >> 5) - 1;
	if (id < 0 || id >= ETP_MAX_FINGERS)
		return;

	etd->mt[id].x = ((packet[1] & 0x0f) << 8) | packet[2];
	etd->mt[id].y = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
	traces = (packet[0] & 0xf0) >> 4;

	input_mt_slot(dev, id);
	input_mt_report_slot_state(dev, MT_TOOL_FINGER, true);

	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);
	input_report_abs(dev, ABS_MT_PRESSURE, pres);
	input_report_abs(dev, ABS_MT_TOUCH_MAJOR, traces * etd->width);
	/* report this for backwards compatibility */
	input_report_abs(dev, ABS_TOOL_WIDTH, traces);

	elantech_input_sync_v4(psmouse);
}

static void process_packet_motion_v4(struct psmouse *psmouse)
{
	struct input_dev *dev = psmouse->dev;
	struct elantech_data *etd = psmouse->private;
	unsigned char *packet = psmouse->packet;
	int weight, delta_x1 = 0, delta_y1 = 0, delta_x2 = 0, delta_y2 = 0;
	int id, sid;

	id = ((packet[0] & 0xe0) >> 5) - 1;
	if (id < 0 || id >= ETP_MAX_FINGERS)
		return;

	sid = ((packet[3] & 0xe0) >> 5) - 1;
	weight = (packet[0] & 0x10) ? ETP_WEIGHT_VALUE : 1;
	/*
	 * Motion packets give us the delta of x, y values of specific fingers,
	 * but in two's complement. Let the compiler do the conversion for us.
	 * Also _enlarge_ the numbers to int, in case of overflow.
	 */
	delta_x1 = (signed char)packet[1];
	delta_y1 = (signed char)packet[2];
	delta_x2 = (signed char)packet[4];
	delta_y2 = (signed char)packet[5];

	etd->mt[id].x += delta_x1 * weight;
	etd->mt[id].y -= delta_y1 * weight;
	input_mt_slot(dev, id);
	input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[id].x);
	input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[id].y);

	if (sid >= 0 && sid < ETP_MAX_FINGERS) {
		etd->mt[sid].x += delta_x2 * weight;
		etd->mt[sid].y -= delta_y2 * weight;
		input_mt_slot(dev, sid);
		input_report_abs(dev, ABS_MT_POSITION_X, etd->mt[sid].x);
		input_report_abs(dev, ABS_MT_POSITION_Y, etd->mt[sid].y);
	}

	elantech_input_sync_v4(psmouse);
}

static void elantech_report_absolute_v4(struct psmouse *psmouse,
					int packet_type)
{
	switch (packet_type) {
	case PACKET_V4_STATUS:
		process_packet_status_v4(psmouse);
		break;

	case PACKET_V4_HEAD:
		process_packet_head_v4(psmouse);
		break;

	case PACKET_V4_MOTION:
		process_packet_motion_v4(psmouse);
		break;

	case PACKET_UNKNOWN:
	default:
		/* impossible to get here */
		break;
	}
}

static int elantech_packet_check_v1(struct psmouse *psmouse)
{
	struct elantech_data *etd = psmouse->private;
	unsigned char *packet = psmouse->packet;
	unsigned char p1, p2, p3;

	/* Parity bits are placed differently */
	if (etd->info.fw_version < 0x020000) {
		/* byte 0:  D   U  p1  p2   1  p3   R   L */
		p1 = (packet[0] & 0x20) >> 5;
		p2 = (packet[0] & 0x10) >> 4;
	} else {
		/* byte 0: n1  n0  p2  p1   1  p3   R   L */
		p1 = (packet[0] & 0x10) >> 4;
		p2 = (packet[0] & 0x20) >> 5;
	}

	p3 = (packet[0] & 0x04) >> 2;

	return etd->parity[packet[1]] == p1 &&
	       etd->parity[packet[2]] == p2 &&
	       etd->parity[packet[3]] == p3;
}

static int elantech_debounce_check_v2(struct psmouse *psmouse)
{
        /*
         * When we encounter packet that matches this exactly, it means the
         * hardware is in debounce status. Just ignore the whole packet.
         */
	static const u8 debounce_packet[] = {
		0x84, 0xff, 0xff, 0x02, 0xff, 0xff
	};
        unsigned char *packet = psmouse->packet;

        return !memcmp(packet, debounce_packet, sizeof(debounce_packet));
}

static int elantech_packet_check_v2(struct psmouse *psmouse)
{
	struct elantech_data *etd = psmouse->private;
	unsigned char *packet = psmouse->packet;

	/*
	 * V2 hardware has two flavors. Older ones that do not report pressure,
	 * and newer ones that reports pressure and width. With newer ones, all
	 * packets (1, 2, 3 finger touch) have the same constant bits. With
	 * older ones, 1/3 finger touch packets and 2 finger touch packets
	 * have different constant bits.
	 * With all three cases, if the constant bits are not exactly what I
	 * expected, I consider them invalid.
	 */
	if (etd->info.reports_pressure)
		return (packet[0] & 0x0c) == 0x04 &&
		       (packet[3] & 0x0f) == 0x02;

	if ((packet[0] & 0xc0) == 0x80)
		return (packet[0] & 0x0c) == 0x0c &&
		       (packet[3] & 0x0e) == 0x08;

	return (packet[0] & 0x3c) == 0x3c &&
	       (packet[1] & 0xf0) == 0x00 &&
	       (packet[3] & 0x3e) == 0x38 &&
	       (packet[4] & 0xf0) == 0x00;
}

/*
 * We check the constant bits to determine what packet type we get,
 * so packet checking is mandatory for v3 and later hardware.
 */
static int elantech_packet_check_v3(struct psmouse *psmouse)
{
	struct elantech_data *etd = psmouse->private;
	static const u8 debounce_packet[] = {
		0xc4, 0xff, 0xff, 0x02, 0xff, 0xff
	};
	unsigned char *packet = psmouse->packet;

	/*
	 * check debounce first, it has the same signature in byte 0
	 * and byte 3 as PACKET_V3_HEAD.
	 */
	if (!memcmp(packet, debounce_packet, sizeof(debounce_packet)))
		return PACKET_DEBOUNCE;

	/*
	 * If the hardware flag 'crc_enabled' is set the packets have
	 * different signatures.
	 */
	if (etd->info.crc_enabled) {
		if ((packet[3] & 0x09) == 0x08)
			return PACKET_V3_HEAD;

		if ((packet[3] & 0x09) == 0x09)
			return PACKET_V3_TAIL;
	} else {
		if ((packet[0] & 0x0c) == 0x04 && (packet[3] & 0xcf) == 0x02)
			return PACKET_V3_HEAD;

		if ((packet[0] & 0x0c) == 0x0c && (packet[3] & 0xce) == 0x0c)
			return PACKET_V3_TAIL;
		if ((packet[3] & 0x0f) == 0x06)
			return PACKET_TRACKPOINT;
	}

	return PACKET_UNKNOWN;
}

static int elantech_packet_check_v4(struct psmouse *psmouse)
{
	struct elantech_data *etd = psmouse->private;
	unsigned char *packet = psmouse->packet;
	unsigned char packet_type = packet[3] & 0x03;
	unsigned int ic_version;
	bool sanity_check;

	if (etd->tp_dev && (packet[3] & 0x0f) == 0x06)
		return PACKET_TRACKPOINT;

	/* This represents the version of IC body. */
	ic_version = (etd->info.fw_version & 0x0f0000) >> 16;

	/*
	 * Sanity check based on the constant bits of a packet.
	 * The constant bits change depending on the value of
	 * the hardware flag 'crc_enabled' and the version of
	 * the IC body, but are the same for every packet,
	 * regardless of the type.
	 */
	if (etd->info.crc_enabled)
		sanity_check = ((packet[3] & 0x08) == 0x00);
	else if (ic_version == 7 && etd->info.samples[1] == 0x2A)
		sanity_check = ((packet[3] & 0x1c) == 0x10);
	else
		sanity_check = ((packet[0] & 0x08) == 0x00 &&
				(packet[3] & 0x1c) == 0x10);

	if (!sanity_check)
		return PACKET_UNKNOWN;

	switch (packet_type) {
	case 0:
		return PACKET_V4_STATUS;

	case 1:
		return PACKET_V4_HEAD;

	case 2:
		return PACKET_V4_MOTION;
	}

	return PACKET_UNKNOWN;
}

/*
 * Process byte stream from mouse and handle complete packets
 */
static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
{
	struct elantech_data *etd = psmouse->private;
	int packet_type;

	if (psmouse->pktcnt < psmouse->pktsize)
		return PSMOUSE_GOOD_DATA;

	if (etd->info.debug > 1)
		elantech_packet_dump(psmouse);

	switch (etd->info.hw_version) {
	case 1:
		if (etd->info.paritycheck && !elantech_packet_check_v1(psmouse))
			return PSMOUSE_BAD_DATA;

		elantech_report_absolute_v1(psmouse);
		break;

	case 2:
		/* ignore debounce */
		if (elantech_debounce_check_v2(psmouse))
			return PSMOUSE_FULL_PACKET;

		if (etd->info.paritycheck && !elantech_packet_check_v2(psmouse))
			return PSMOUSE_BAD_DATA;

		elantech_report_absolute_v2(psmouse);
		break;

	case 3:
		packet_type = elantech_packet_check_v3(psmouse);
		switch (packet_type) {
		case PACKET_UNKNOWN:
			return PSMOUSE_BAD_DATA;

		case PACKET_DEBOUNCE:
			/* ignore debounce */
			break;

		case PACKET_TRACKPOINT:
			elantech_report_trackpoint(psmouse, packet_type);
			break;

		default:
			elantech_report_absolute_v3(psmouse, packet_type);
			break;
		}

		break;

	case 4:
		packet_type = elantech_packet_check_v4(psmouse);
		switch (packet_type) {
		case PACKET_UNKNOWN:
			return PSMOUSE_BAD_DATA;

		case PACKET_TRACKPOINT:
			elantech_report_trackpoint(psmouse, packet_type);
			break;

		default:
			elantech_report_absolute_v4(psmouse, packet_type);
			break;
		}

		break;
	}

	return PSMOUSE_FULL_PACKET;
}

/*
 * This writes the reg_07 value again to the hardware at the end of every
 * set_rate call because the register loses its value. reg_07 allows setting
 * absolute mode on v4 hardware
 */
static void elantech_set_rate_restore_reg_07(struct psmouse *psmouse,
		unsigned int rate)
{
	struct elantech_data *etd = psmouse->private;

	etd->original_set_rate(psmouse, rate);
	if (elantech_write_reg(psmouse, 0x07, etd->reg_07))
		psmouse_err(psmouse, "restoring reg_07 failed\n");
}

/*
 * Put the touchpad into absolute mode
 */
static int elantech_set_absolute_mode(struct psmouse *psmouse)
{
	struct elantech_data *etd = psmouse->private;
	unsigned char val;
	int tries = ETP_READ_BACK_TRIES;
	int rc = 0;

	switch (etd->info.hw_version) {
	case 1:
		etd->reg_10 = 0x16;
		etd->reg_11 = 0x8f;
		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
		    elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
			rc = -1;
		}
		break;

	case 2:
					/* Windows driver values */
		etd->reg_10 = 0x54;
		etd->reg_11 = 0x88;	/* 0x8a */
		etd->reg_21 = 0x60;	/* 0x00 */
		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
		    elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
		    elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
			rc = -1;
		}
		break;

	case 3:
		if (etd->info.set_hw_resolution)
			etd->reg_10 = 0x0b;
		else
			etd->reg_10 = 0x01;

		if (elantech_write_reg(psmouse, 0x10, etd->reg_10))
			rc = -1;

		break;

	case 4:
		etd->reg_07 = 0x01;
		if (elantech_write_reg(psmouse, 0x07, etd->reg_07))
			rc = -1;

		goto skip_readback_reg_10; /* v4 has no reg 0x10 to read */
	}

	if (rc == 0) {
		/*
		 * Read back reg 0x10. For hardware version 1 we must make
		 * sure the absolute mode bit is set. For hardware version 2
		 * the touchpad is probably initializing and not ready until
		 * we read back the value we just wrote.
		 */
		do {
			rc = elantech_read_reg(psmouse, 0x10, &val);
			if (rc == 0)
				break;
			tries--;
			elantech_debug("retrying read (%d).\n", tries);
			msleep(ETP_READ_BACK_DELAY);
		} while (tries > 0);

		if (rc) {
			psmouse_err(psmouse,
				    "failed to read back register 0x10.\n");
		} else if (etd->info.hw_version == 1 &&
			   !(val & ETP_R10_ABSOLUTE_MODE)) {
			psmouse_err(psmouse,
				    "touchpad refuses to switch to absolute mode.\n");
			rc = -1;
		}
	}

 skip_readback_reg_10:
	if (rc)
		psmouse_err(psmouse, "failed to initialise registers.\n");

	return rc;
}

/*
 * (value from firmware) * 10 + 790 = dpi
 * we also have to convert dpi to dots/mm (*10/254 to avoid floating point)
 */
static unsigned int elantech_convert_res(unsigned int val)
{
	return (val * 10 + 790) * 10 / 254;
}

static int elantech_get_resolution_v4(struct psmouse *psmouse,
				      unsigned int *x_res,
				      unsigned int *y_res,
				      unsigned int *bus)
{
	unsigned char param[3];

	if (elantech_send_cmd(psmouse, ETP_RESOLUTION_QUERY, param))
		return -1;

	*x_res = elantech_convert_res(param[1] & 0x0f);
	*y_res = elantech_convert_res((param[1] & 0xf0) >> 4);
	*bus = param[2];

	return 0;
}

static void elantech_set_buttonpad_prop(struct psmouse *psmouse)
{
	struct input_dev *dev = psmouse->dev;
	struct elantech_data *etd = psmouse->private;

	if (elantech_is_buttonpad(&etd->info)) {
		__set_bit(INPUT_PROP_BUTTONPAD, dev->propbit);
		__clear_bit(BTN_RIGHT, dev->keybit);
	}
}

/*
 * Some hw_version 4 models do have a middle button
 */
static const struct dmi_system_id elantech_dmi_has_middle_button[] = {
#if defined(CONFIG_DMI) && defined(CONFIG_X86)
	{
		/* Fujitsu H730 has a middle button */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H730"),
		},
	},
	{
		/* Fujitsu H760 also has a middle button */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H760"),
		},
	},
	{
		/* Fujitsu H780 also has a middle button */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H780"),
		},
	},
#endif
	{ }
};

/*
 * Set the appropriate event bits for the input subsystem
 */
static int elantech_set_input_params(struct psmouse *psmouse)
{
	struct input_dev *dev = psmouse->dev;
	struct elantech_data *etd = psmouse->private;
	struct elantech_device_info *info = &etd->info;
	unsigned int x_min = info->x_min, y_min = info->y_min,
		     x_max = info->x_max, y_max = info->y_max,
		     width = info->width;

	__set_bit(INPUT_PROP_POINTER, dev->propbit);
	__set_bit(EV_KEY, dev->evbit);
	__set_bit(EV_ABS, dev->evbit);
	__clear_bit(EV_REL, dev->evbit);

	__set_bit(BTN_LEFT, dev->keybit);
	if (info->has_middle_button)
		__set_bit(BTN_MIDDLE, dev->keybit);
	__set_bit(BTN_RIGHT, dev->keybit);

	__set_bit(BTN_TOUCH, dev->keybit);
	__set_bit(BTN_TOOL_FINGER, dev->keybit);
	__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
	__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);

	switch (info->hw_version) {
	case 1:
		/* Rocker button */
		if (info->fw_version < 0x020000 &&
		    (info->capabilities[0] & ETP_CAP_HAS_ROCKER)) {
			__set_bit(BTN_FORWARD, dev->keybit);
			__set_bit(BTN_BACK, dev->keybit);
		}
		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
		break;

	case 2:
		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
		__set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
		fallthrough;
	case 3:
		if (info->hw_version == 3)
			elantech_set_buttonpad_prop(psmouse);
		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
		if (info->reports_pressure) {
			input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
					     ETP_PMAX_V2, 0, 0);
			input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
					     ETP_WMAX_V2, 0, 0);
		}
		input_mt_init_slots(dev, 2, INPUT_MT_SEMI_MT);
		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
		break;

	case 4:
		elantech_set_buttonpad_prop(psmouse);
		__set_bit(BTN_TOOL_QUADTAP, dev->keybit);
		/* For X to recognize me as touchpad. */
		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
		/*
		 * range of pressure and width is the same as v2,
		 * report ABS_PRESSURE, ABS_TOOL_WIDTH for compatibility.
		 */
		input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
				     ETP_PMAX_V2, 0, 0);
		input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
				     ETP_WMAX_V2, 0, 0);
		/* Multitouch capable pad, up to 5 fingers. */
		input_mt_init_slots(dev, ETP_MAX_FINGERS, 0);
		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
		input_set_abs_params(dev, ABS_MT_PRESSURE, ETP_PMIN_V2,
				     ETP_PMAX_V2, 0, 0);
		/*
		 * The firmware reports how many trace lines the finger spans,
		 * convert to surface unit as Protocol-B requires.
		 */
		input_set_abs_params(dev, ABS_MT_TOUCH_MAJOR, 0,
				     ETP_WMAX_V2 * width, 0, 0);
		break;
	}

	input_abs_set_res(dev, ABS_X, info->x_res);
	input_abs_set_res(dev, ABS_Y, info->y_res);
	if (info->hw_version > 1) {
		input_abs_set_res(dev, ABS_MT_POSITION_X, info->x_res);
		input_abs_set_res(dev, ABS_MT_POSITION_Y, info->y_res);
	}

	etd->y_max = y_max;
	etd->width = width;

	return 0;
}

struct elantech_attr_data {
	size_t		field_offset;
	unsigned char	reg;
};

/*
 * Display a register value by reading a sysfs entry
 */
static ssize_t elantech_show_int_attr(struct psmouse *psmouse, void *data,
					char *buf)
{
	struct elantech_data *etd = psmouse->private;
	struct elantech_attr_data *attr = data;
	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
	int rc = 0;

	if (attr->reg)
		rc = elantech_read_reg(psmouse, attr->reg, reg);

	return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
}

/*
 * Write a register value by writing a sysfs entry
 */
static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
				     void *data, const char *buf, size_t count)
{
	struct elantech_data *etd = psmouse->private;
	struct elantech_attr_data *attr = data;
	unsigned char *reg = (unsigned char *) etd + attr->field_offset;
	unsigned char value;
	int err;

	err = kstrtou8(buf, 16, &value);
	if (err)
		return err;

	/* Do we need to preserve some bits for version 2 hardware too? */
	if (etd->info.hw_version == 1) {
		if (attr->reg == 0x10)
			/* Force absolute mode always on */
			value |= ETP_R10_ABSOLUTE_MODE;
		else if (attr->reg == 0x11)
			/* Force 4 byte mode always on */
			value |= ETP_R11_4_BYTE_MODE;
	}

	if (!attr->reg || elantech_write_reg(psmouse, attr->reg, value) == 0)
		*reg = value;

	return count;
}

#define ELANTECH_INT_ATTR(_name, _register)				\
	static struct elantech_attr_data elantech_attr_##_name = {	\
		.field_offset = offsetof(struct elantech_data, _name),	\
		.reg = _register,					\
	};								\
	PSMOUSE_DEFINE_ATTR(_name, 0644,				\
			    &elantech_attr_##_name,			\
			    elantech_show_int_attr,			\
			    elantech_set_int_attr)

#define ELANTECH_INFO_ATTR(_name)					       \
	static struct elantech_attr_data elantech_attr_##_name = {	       \
		.field_offset = offsetof(struct elantech_data, info) +	       \
				offsetof(struct elantech_device_info, _name),  \
		.reg = 0,						       \
	};								       \
	PSMOUSE_DEFINE_ATTR(_name, 0644,				       \
			    &elantech_attr_##_name,			       \
			    elantech_show_int_attr,			       \
			    elantech_set_int_attr)

ELANTECH_INT_ATTR(reg_07, 0x07);
ELANTECH_INT_ATTR(reg_10, 0x10);
ELANTECH_INT_ATTR(reg_11, 0x11);
ELANTECH_INT_ATTR(reg_20, 0x20);
ELANTECH_INT_ATTR(reg_21, 0x21);
ELANTECH_INT_ATTR(reg_22, 0x22);
ELANTECH_INT_ATTR(reg_23, 0x23);
ELANTECH_INT_ATTR(reg_24, 0x24);
ELANTECH_INT_ATTR(reg_25, 0x25);
ELANTECH_INT_ATTR(reg_26, 0x26);
ELANTECH_INFO_ATTR(debug);
ELANTECH_INFO_ATTR(paritycheck);
ELANTECH_INFO_ATTR(crc_enabled);

static struct attribute *elantech_attrs[] = {
	&psmouse_attr_reg_07.dattr.attr,
	&psmouse_attr_reg_10.dattr.attr,
	&psmouse_attr_reg_11.dattr.attr,
	&psmouse_attr_reg_20.dattr.attr,
	&psmouse_attr_reg_21.dattr.attr,
	&psmouse_attr_reg_22.dattr.attr,
	&psmouse_attr_reg_23.dattr.attr,
	&psmouse_attr_reg_24.dattr.attr,
	&psmouse_attr_reg_25.dattr.attr,
	&psmouse_attr_reg_26.dattr.attr,
	&psmouse_attr_debug.dattr.attr,
	&psmouse_attr_paritycheck.dattr.attr,
	&psmouse_attr_crc_enabled.dattr.attr,
	NULL
};

static const struct attribute_group elantech_attr_group = {
	.attrs = elantech_attrs,
};

static bool elantech_is_signature_valid(const unsigned char *param)
{
	static const unsigned char rates[] = { 200, 100, 80, 60, 40, 20, 10 };
	int i;

	if (param[0] == 0)
		return false;

	if (param[1] == 0)
		return true;

	/*
	 * Some hw_version >= 4 models have a revision higher then 20. Meaning
	 * that param[2] may be 10 or 20, skip the rates check for these.
	 */
	if ((param[0] & 0x0f) >= 0x06 && (param[1] & 0xaf) == 0x0f &&
	    param[2] < 40)
		return true;

	for (i = 0; i < ARRAY_SIZE(rates); i++)
		if (param[2] == rates[i])
			return false;

	return true;
}

/*
 * Use magic knock to detect Elantech touchpad
 */
int elantech_detect(struct psmouse *psmouse, bool set_properties)
{
	struct ps2dev *ps2dev = &psmouse->ps2dev;
	unsigned char param[3];

	ps2_command(ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);

	if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_DISABLE) ||
	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
		psmouse_dbg(psmouse, "sending Elantech magic knock failed.\n");
		return -1;
	}

	/*
	 * Report this in case there are Elantech models that use a different
	 * set of magic numbers
	 */
	if (param[0] != 0x3c || param[1] != 0x03 ||
	    (param[2] != 0xc8 && param[2] != 0x00)) {
		psmouse_dbg(psmouse,
			    "unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
			    param[0], param[1], param[2]);
		return -1;
	}

	/*
	 * Query touchpad's firmware version and see if it reports known
	 * value to avoid mis-detection. Logitech mice are known to respond
	 * to Elantech magic knock and there might be more.
	 */
	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
		psmouse_dbg(psmouse, "failed to query firmware version.\n");
		return -1;
	}

	psmouse_dbg(psmouse,
		    "Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
		    param[0], param[1], param[2]);

	if (!elantech_is_signature_valid(param)) {
		psmouse_dbg(psmouse,
			    "Probably not a real Elantech touchpad. Aborting.\n");
		return -1;
	}

	if (set_properties) {
		psmouse->vendor = "Elantech";
		psmouse->name = "Touchpad";
	}

	return 0;
}

/*
 * Clean up sysfs entries when disconnecting
 */
static void elantech_disconnect(struct psmouse *psmouse)
{
	struct elantech_data *etd = psmouse->private;

	/*
	 * We might have left a breadcrumb when trying to
	 * set up SMbus companion.
	 */
	psmouse_smbus_cleanup(psmouse);

	if (etd->tp_dev)
		input_unregister_device(etd->tp_dev);
	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
			   &elantech_attr_group);
	kfree(psmouse->private);
	psmouse->private = NULL;
}

/*
 * Put the touchpad back into absolute mode when reconnecting
 */
static int elantech_reconnect(struct psmouse *psmouse)
{
	psmouse_reset(psmouse);

	if (elantech_detect(psmouse, 0))
		return -1;

	if (elantech_set_absolute_mode(psmouse)) {
		psmouse_err(psmouse,
			    "failed to put touchpad back into absolute mode.\n");
		return -1;
	}

	return 0;
}

/*
 * Some hw_version 4 models do not work with crc_disabled
 */
static const struct dmi_system_id elantech_dmi_force_crc_enabled[] = {
#if defined(CONFIG_DMI) && defined(CONFIG_X86)
	{
		/* Fujitsu H730 does not work with crc_enabled == 0 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H730"),
		},
	},
	{
		/* Fujitsu H760 does not work with crc_enabled == 0 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
			DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H760"),
		},
	},
	{
		/* Fujitsu LIFEBOOK E544  does not work with crc_enabled == 0 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E544"),
		},
	},
	{
		/* Fujitsu LIFEBOOK E546  does not work with crc_enabled == 0 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E546"),
		},
	},
	{
		/* Fujitsu LIFEBOOK E547 does not work with crc_enabled == 0 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E547"),
		},
	},
	{
		/* Fujitsu LIFEBOOK E554  does not work with crc_enabled == 0 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E554"),
		},
	},
	{
		/* Fujitsu LIFEBOOK E556 does not work with crc_enabled == 0 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E556"),
		},
	},
	{
		/* Fujitsu LIFEBOOK E557 does not work with crc_enabled == 0 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E557"),
		},
	},
	{
		/* Fujitsu LIFEBOOK U745 does not work with crc_enabled == 0 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK U745"),
		},
	},
#endif
	{ }
};

/*
 * Some hw_version 3 models go into error state when we try to set
 * bit 3 and/or bit 1 of r10.
 */
static const struct dmi_system_id no_hw_res_dmi_table[] = {
#if defined(CONFIG_DMI) && defined(CONFIG_X86)
	{
		/* Gigabyte U2442 */
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
			DMI_MATCH(DMI_PRODUCT_NAME, "U2442"),
		},
	},
#endif
	{ }
};

/*
 * Change Report id 0x5E to 0x5F.
 */
static int elantech_change_report_id(struct psmouse *psmouse)
{
	/*
	 * NOTE: the code is expecting to receive param[] as an array of 3
	 * items (see __ps2_command()), even if in this case only 2 are
	 * actually needed. Make sure the array size is 3 to avoid potential
	 * stack out-of-bound accesses.
	 */
	unsigned char param[3] = { 0x10, 0x03 };

	if (elantech_write_reg_params(psmouse, 0x7, param) ||
	    elantech_read_reg_params(psmouse, 0x7, param) ||
	    param[0] != 0x10 || param[1] != 0x03) {
		psmouse_err(psmouse, "Unable to change report ID to 0x5f.\n");
		return -EIO;
	}

	return 0;
}
/*
 * determine hardware version and set some properties according to it.
 */
static int elantech_set_properties(struct elantech_device_info *info)
{
	/* This represents the version of IC body. */
	info->ic_version = (info->fw_version & 0x0f0000) >> 16;

	/* Early version of Elan touchpads doesn't obey the rule. */
	if (info->fw_version < 0x020030 || info->fw_version == 0x020600)
		info->hw_version = 1;
	else {
		switch (info->ic_version) {
		case 2:
		case 4:
			info->hw_version = 2;
			break;
		case 5:
			info->hw_version = 3;
			break;
		case 6 ... 15:
			info->hw_version = 4;
			break;
		default:
			return -1;
		}
	}

	/* Get information pattern for hw_version 4 */
	info->pattern = 0x00;
	if (info->ic_version == 0x0f && (info->fw_version & 0xff) <= 0x02)
		info->pattern = info->fw_version & 0xff;

	/* decide which send_cmd we're gonna use early */
	info->send_cmd = info->hw_version >= 3 ? elantech_send_cmd :
						 synaptics_send_cmd;

	/* Turn on packet checking by default */
	info->paritycheck = 1;

	/*
	 * This firmware suffers from misreporting coordinates when
	 * a touch action starts causing the mouse cursor or scrolled page
	 * to jump. Enable a workaround.
	 */
	info->jumpy_cursor =
		(info->fw_version == 0x020022 || info->fw_version == 0x020600);

	if (info->hw_version > 1) {
		/* For now show extra debug information */
		info->debug = 1;

		if (info->fw_version >= 0x020800)
			info->reports_pressure = true;
	}

	/*
	 * The signatures of v3 and v4 packets change depending on the
	 * value of this hardware flag.
	 */
	info->crc_enabled = (info->fw_version & 0x4000) == 0x4000 ||
			     dmi_check_system(elantech_dmi_force_crc_enabled);

	/* Enable real hardware resolution on hw_version 3 ? */
	info->set_hw_resolution = !dmi_check_system(no_hw_res_dmi_table);

	return 0;
}

static int elantech_query_info(struct psmouse *psmouse,
			       struct elantech_device_info *info)
{
	unsigned char param[3];
	unsigned char traces;
	unsigned char ic_body[3];

	memset(info, 0, sizeof(*info));

	/*
	 * Do the version query again so we can store the result
	 */
	if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
		psmouse_err(psmouse, "failed to query firmware version.\n");
		return -EINVAL;
	}
	info->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];

	if (elantech_set_properties(info)) {
		psmouse_err(psmouse, "unknown hardware version, aborting...\n");
		return -EINVAL;
	}
	psmouse_info(psmouse,
		     "assuming hardware version %d (with firmware version 0x%02x%02x%02x)\n",
		     info->hw_version, param[0], param[1], param[2]);

	if (info->send_cmd(psmouse, ETP_CAPABILITIES_QUERY,
	    info->capabilities)) {
		psmouse_err(psmouse, "failed to query capabilities.\n");
		return -EINVAL;
	}
	psmouse_info(psmouse,
		     "Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
		     info->capabilities[0], info->capabilities[1],
		     info->capabilities[2]);

	if (info->hw_version != 1) {
		if (info->send_cmd(psmouse, ETP_SAMPLE_QUERY, info->samples)) {
			psmouse_err(psmouse, "failed to query sample data\n");
			return -EINVAL;
		}
		psmouse_info(psmouse,
			     "Elan sample query result %02x, %02x, %02x\n",
			     info->samples[0],
			     info->samples[1],
			     info->samples[2]);
	}

	if (info->pattern > 0x00 && info->ic_version == 0xf) {
		if (info->send_cmd(psmouse, ETP_ICBODY_QUERY, ic_body)) {
			psmouse_err(psmouse, "failed to query ic body\n");
			return -EINVAL;
		}
		info->ic_version = be16_to_cpup((__be16 *)ic_body);
		psmouse_info(psmouse,
			     "Elan ic body: %#04x, current fw version: %#02x\n",
			     info->ic_version, ic_body[2]);
	}

	info->product_id = be16_to_cpup((__be16 *)info->samples);
	if (info->pattern == 0x00)
		info->product_id &= 0xff;

	if (info->samples[1] == 0x74 && info->hw_version == 0x03) {
		/*
		 * This module has a bug which makes absolute mode
		 * unusable, so let's abort so we'll be using standard
		 * PS/2 protocol.
		 */
		psmouse_info(psmouse,
			     "absolute mode broken, forcing standard PS/2 protocol\n");
		return -ENODEV;
	}

	/* The MSB indicates the presence of the trackpoint */
	info->has_trackpoint = (info->capabilities[0] & 0x80) == 0x80;

	if (info->has_trackpoint && info->ic_version == 0x0011 &&
	    (info->product_id == 0x08 || info->product_id == 0x09 ||
	     info->product_id == 0x0d || info->product_id == 0x0e)) {
		/*
		 * This module has a bug which makes trackpoint in SMBus
		 * mode return invalid data unless trackpoint is switched
		 * from using 0x5e reports to 0x5f. If we are not able to
		 * make the switch, let's abort initialization so we'll be
		 * using standard PS/2 protocol.
		 */
		if (elantech_change_report_id(psmouse)) {
			psmouse_info(psmouse,
				     "Trackpoint report is broken, forcing standard PS/2 protocol\n");
			return -ENODEV;
		}
	}

	info->x_res = 31;
	info->y_res = 31;
	if (info->hw_version == 4) {
		if (elantech_get_resolution_v4(psmouse,
					       &info->x_res,
					       &info->y_res,
					       &info->bus)) {
			psmouse_warn(psmouse,
				     "failed to query resolution data.\n");
		}
	}

	/* query range information */
	switch (info->hw_version) {
	case 1:
		info->x_min = ETP_XMIN_V1;
		info->y_min = ETP_YMIN_V1;
		info->x_max = ETP_XMAX_V1;
		info->y_max = ETP_YMAX_V1;
		break;

	case 2:
		if (info->fw_version == 0x020800 ||
		    info->fw_version == 0x020b00 ||
		    info->fw_version == 0x020030) {
			info->x_min = ETP_XMIN_V2;
			info->y_min = ETP_YMIN_V2;
			info->x_max = ETP_XMAX_V2;
			info->y_max = ETP_YMAX_V2;
		} else {
			int i;
			int fixed_dpi;

			i = (info->fw_version > 0x020800 &&
			     info->fw_version < 0x020900) ? 1 : 2;

			if (info->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
				return -EINVAL;

			fixed_dpi = param[1] & 0x10;

			if (((info->fw_version >> 16) == 0x14) && fixed_dpi) {
				if (info->send_cmd(psmouse, ETP_SAMPLE_QUERY, param))
					return -EINVAL;

				info->x_max = (info->capabilities[1] - i) * param[1] / 2;
				info->y_max = (info->capabilities[2] - i) * param[2] / 2;
			} else if (info->fw_version == 0x040216) {
				info->x_max = 819;
				info->y_max = 405;
			} else if (info->fw_version == 0x040219 || info->fw_version == 0x040215) {
				info->x_max = 900;
				info->y_max = 500;
			} else {
				info->x_max = (info->capabilities[1] - i) * 64;
				info->y_max = (info->capabilities[2] - i) * 64;
			}
		}
		break;

	case 3:
		if (info->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
			return -EINVAL;

		info->x_max = (0x0f & param[0]) << 8 | param[1];
		info->y_max = (0xf0 & param[0]) << 4 | param[2];
		break;

	case 4:
		if (info->send_cmd(psmouse, ETP_FW_ID_QUERY, param))
			return -EINVAL;

		info->x_max = (0x0f & param[0]) << 8 | param[1];
		info->y_max = (0xf0 & param[0]) << 4 | param[2];
		traces = info->capabilities[1];
		if ((traces < 2) || (traces > info->x_max))
			return -EINVAL;

		info->width = info->x_max / (traces - 1);

		/* column number of traces */
		info->x_traces = traces;

		/* row number of traces */
		traces = info->capabilities[2];
		if ((traces >= 2) && (traces <= info->y_max))
			info->y_traces = traces;

		break;
	}

	/* check for the middle button: DMI matching or new v4 firmwares */
	info->has_middle_button = dmi_check_system(elantech_dmi_has_middle_button) ||
				  (ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version) &&
				   !elantech_is_buttonpad(info));

	return 0;
}

#if defined(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)

/*
 * The newest Elantech device can use a secondary bus (over SMBus) which
 * provides a better bandwidth and allow a better control of the touchpads.
 * This is used to decide if we need to use this bus or not.
 */
enum {
	ELANTECH_SMBUS_NOT_SET = -1,
	ELANTECH_SMBUS_OFF,
	ELANTECH_SMBUS_ON,
};

static int elantech_smbus = IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_SMBUS) ?
		ELANTECH_SMBUS_NOT_SET : ELANTECH_SMBUS_OFF;
module_param_named(elantech_smbus, elantech_smbus, int, 0644);
MODULE_PARM_DESC(elantech_smbus, "Use a secondary bus for the Elantech device.");

static const char * const i2c_blacklist_pnp_ids[] = {
	/*
	 * These are known to not be working properly as bits are missing
	 * in elan_i2c.
	 */
	NULL
};

static int elantech_create_smbus(struct psmouse *psmouse,
				 struct elantech_device_info *info,
				 bool leave_breadcrumbs)
{
	struct property_entry i2c_props[11] = {};
	struct i2c_board_info smbus_board = {
		I2C_BOARD_INFO("elan_i2c", 0x15),
		.flags = I2C_CLIENT_HOST_NOTIFY,
	};
	unsigned int idx = 0;

	i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-size-x",
						   info->x_max + 1);
	i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-size-y",
						   info->y_max + 1);
	i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-min-x",
						   info->x_min);
	i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-min-y",
						   info->y_min);
	if (info->x_res)
		i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-x-mm",
						      (info->x_max + 1) / info->x_res);
	if (info->y_res)
		i2c_props[idx++] = PROPERTY_ENTRY_U32("touchscreen-y-mm",
						      (info->y_max + 1) / info->y_res);

	if (info->has_trackpoint)
		i2c_props[idx++] = PROPERTY_ENTRY_BOOL("elan,trackpoint");

	if (info->has_middle_button)
		i2c_props[idx++] = PROPERTY_ENTRY_BOOL("elan,middle-button");

	if (info->x_traces)
		i2c_props[idx++] = PROPERTY_ENTRY_U32("elan,x_traces",
						      info->x_traces);
	if (info->y_traces)
		i2c_props[idx++] = PROPERTY_ENTRY_U32("elan,y_traces",
						      info->y_traces);

	if (elantech_is_buttonpad(info))
		i2c_props[idx++] = PROPERTY_ENTRY_BOOL("elan,clickpad");

	smbus_board.fwnode = fwnode_create_software_node(i2c_props, NULL);
	if (IS_ERR(smbus_board.fwnode))
		return PTR_ERR(smbus_board.fwnode);

	return psmouse_smbus_init(psmouse, &smbus_board, NULL, 0, false,
				  leave_breadcrumbs);
}

/*
 * elantech_setup_smbus - called once the PS/2 devices are enumerated
 * and decides to instantiate a SMBus InterTouch device.
 */
static int elantech_setup_smbus(struct psmouse *psmouse,
				struct elantech_device_info *info,
				bool leave_breadcrumbs)
{
	int error;

	if (elantech_smbus == ELANTECH_SMBUS_OFF)
		return -ENXIO;

	if (elantech_smbus == ELANTECH_SMBUS_NOT_SET) {
		/*
		 * New ICs are enabled by default, unless mentioned in
		 * i2c_blacklist_pnp_ids.
		 * Old ICs are up to the user to decide.
		 */
		if (!ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version) ||
		    psmouse_matches_pnp_id(psmouse, i2c_blacklist_pnp_ids))
			return -ENXIO;
	}

	psmouse_info(psmouse, "Trying to set up SMBus access\n");

	error = elantech_create_smbus(psmouse, info, leave_breadcrumbs);
	if (error) {
		if (error == -EAGAIN)
			psmouse_info(psmouse, "SMbus companion is not ready yet\n");
		else
			psmouse_err(psmouse, "unable to create intertouch device\n");

		return error;
	}

	return 0;
}

static bool elantech_use_host_notify(struct psmouse *psmouse,
				     struct elantech_device_info *info)
{
	if (ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version))
		return true;

	switch (info->bus) {
	case ETP_BUS_PS2_ONLY:
		/* expected case */
		break;
	case ETP_BUS_SMB_ALERT_ONLY:
	case ETP_BUS_PS2_SMB_ALERT:
		psmouse_dbg(psmouse, "Ignoring SMBus provider through alert protocol.\n");
		break;
	case ETP_BUS_SMB_HST_NTFY_ONLY:
	case ETP_BUS_PS2_SMB_HST_NTFY:
		return true;
	default:
		psmouse_dbg(psmouse,
			    "Ignoring SMBus bus provider %d.\n",
			    info->bus);
	}

	return false;
}

int elantech_init_smbus(struct psmouse *psmouse)
{
	struct elantech_device_info info;
	int error;

	psmouse_reset(psmouse);

	error = elantech_query_info(psmouse, &info);
	if (error)
		goto init_fail;

	if (info.hw_version < 4) {
		error = -ENXIO;
		goto init_fail;
	}

	return elantech_create_smbus(psmouse, &info, false);
 init_fail:
	psmouse_reset(psmouse);
	return error;
}
#endif /* CONFIG_MOUSE_PS2_ELANTECH_SMBUS */

/*
 * Initialize the touchpad and create sysfs entries
 */
static int elantech_setup_ps2(struct psmouse *psmouse,
			      struct elantech_device_info *info)
{
	struct elantech_data *etd;
	int i;
	int error = -EINVAL;
	struct input_dev *tp_dev;

	psmouse->private = etd = kzalloc(sizeof(*etd), GFP_KERNEL);
	if (!etd)
		return -ENOMEM;

	etd->info = *info;

	etd->parity[0] = 1;
	for (i = 1; i < 256; i++)
		etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;

	if (elantech_set_absolute_mode(psmouse)) {
		psmouse_err(psmouse,
			    "failed to put touchpad into absolute mode.\n");
		goto init_fail;
	}

	if (info->fw_version == 0x381f17) {
		etd->original_set_rate = psmouse->set_rate;
		psmouse->set_rate = elantech_set_rate_restore_reg_07;
	}

	if (elantech_set_input_params(psmouse)) {
		psmouse_err(psmouse, "failed to query touchpad range.\n");
		goto init_fail;
	}

	error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
				   &elantech_attr_group);
	if (error) {
		psmouse_err(psmouse,
			    "failed to create sysfs attributes, error: %d.\n",
			    error);
		goto init_fail;
	}

	if (info->has_trackpoint) {
		tp_dev = input_allocate_device();

		if (!tp_dev) {
			error = -ENOMEM;
			goto init_fail_tp_alloc;
		}

		etd->tp_dev = tp_dev;
		snprintf(etd->tp_phys, sizeof(etd->tp_phys), "%s/input1",
			psmouse->ps2dev.serio->phys);
		tp_dev->phys = etd->tp_phys;
		tp_dev->name = "ETPS/2 Elantech TrackPoint";
		tp_dev->id.bustype = BUS_I8042;
		tp_dev->id.vendor  = 0x0002;
		tp_dev->id.product = PSMOUSE_ELANTECH;
		tp_dev->id.version = 0x0000;
		tp_dev->dev.parent = &psmouse->ps2dev.serio->dev;
		tp_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
		tp_dev->relbit[BIT_WORD(REL_X)] =
			BIT_MASK(REL_X) | BIT_MASK(REL_Y);
		tp_dev->keybit[BIT_WORD(BTN_LEFT)] =
			BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_MIDDLE) |
			BIT_MASK(BTN_RIGHT);

		__set_bit(INPUT_PROP_POINTER, tp_dev->propbit);
		__set_bit(INPUT_PROP_POINTING_STICK, tp_dev->propbit);

		error = input_register_device(etd->tp_dev);
		if (error < 0)
			goto init_fail_tp_reg;
	}

	psmouse->protocol_handler = elantech_process_byte;
	psmouse->disconnect = elantech_disconnect;
	psmouse->reconnect = elantech_reconnect;
	psmouse->fast_reconnect = NULL;
	psmouse->pktsize = info->hw_version > 1 ? 6 : 4;

	return 0;
 init_fail_tp_reg:
	input_free_device(tp_dev);
 init_fail_tp_alloc:
	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
			   &elantech_attr_group);
 init_fail:
	kfree(etd);
	return error;
}

int elantech_init_ps2(struct psmouse *psmouse)
{
	struct elantech_device_info info;
	int error;

	psmouse_reset(psmouse);

	error = elantech_query_info(psmouse, &info);
	if (error)
		goto init_fail;

	error = elantech_setup_ps2(psmouse, &info);
	if (error)
		goto init_fail;

	return 0;
 init_fail:
	psmouse_reset(psmouse);
	return error;
}

int elantech_init(struct psmouse *psmouse)
{
	struct elantech_device_info info;
	int error;

	psmouse_reset(psmouse);

	error = elantech_query_info(psmouse, &info);
	if (error)
		goto init_fail;

#if defined(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)

	if (elantech_use_host_notify(psmouse, &info)) {
		if (!IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_SMBUS) ||
		    !IS_ENABLED(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)) {
			psmouse_warn(psmouse,
				     "The touchpad can support a better bus than the too old PS/2 protocol. "
				     "Make sure MOUSE_PS2_ELANTECH_SMBUS and MOUSE_ELAN_I2C_SMBUS are enabled to get a better touchpad experience.\n");
		}
		error = elantech_setup_smbus(psmouse, &info, true);
		if (!error)
			return PSMOUSE_ELANTECH_SMBUS;
	}

#endif /* CONFIG_MOUSE_PS2_ELANTECH_SMBUS */

	error = elantech_setup_ps2(psmouse, &info);
	if (error < 0) {
		/*
		 * Not using any flavor of Elantech support, so clean up
		 * SMbus breadcrumbs, if any.
		 */
		psmouse_smbus_cleanup(psmouse);
		goto init_fail;
	}

	return PSMOUSE_ELANTECH;
 init_fail:
	psmouse_reset(psmouse);
	return error;
}